Multi-Metal Additive Joints Without Brittle Intermetallic Phases
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Solution Overview
Problem
Existing methods for joining dissimilar metallic materials in oil, gas, and petrochemical applications often result in the formation of brittle phases and residual stresses, limiting the effectiveness and applicability of multi-metallic articles due to metallurgical incompatibility and geometric constraints.
Innovation Solution
The method involves additive manufacturing to join dissimilar metallic materials with a porosity of less than 0.1% by volume, utilizing a fast cooling rate to prevent intermetallic brittle phase formation, and optionally incorporating a transition or buffer layer to facilitate fusion without cracks, allowing for the direct bonding of dissimilar metals or metal alloys like iron-based, aluminum-based, and titanium-based alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fusion welding processes are used to join dissimilar metallic materials, then the metallic materials can be bonded together, but intermetallic brittle phases form at the interface reducing joint strength
Solution Approach 1:
The patent applies parameter changes by controlling the cooling rate during additive manufacturing to be greater than 100°C per second. This rapid cooling parameter prevents the formation of intermetallic brittle phases at the interface between dissimilar metals, thereby maintaining both joint strength and reliability without the harmful phase formation that occurs in conventional fusion welding.
Solution Approach 2:
The patent creates a composite metallic structure through additive manufacturing that combines dissimilar metallic materials with controlled microstructure. The process produces a composite joint where the rapid cooling creates a refined grain structure and prevents harmful intermetallic phase formation, resulting in a reliable bond between dissimilar metals.
2Strength
If fusion welding processes are used to join dissimilar metallic materials, then the metallic materials can be bonded together, but large residual stresses occur due to physical mismatch
Solution Approach 1:
The patent uses parameter changes by implementing rapid cooling rates (>100°C per second) during additive manufacturing. This controlled thermal parameter reduces the thermal gradient and dwell time at high temperatures, thereby minimizing the physical mismatch effects and reducing residual stress formation while still achieving strong bonds between dissimilar metals.
3Adaptability or versatility
If solid state processes such as friction and friction stir processes are used to join dissimilar metals, then dissimilar metals can be joined, but the processes are limited to articles with relatively simple geometries
Solution Approach 1:
The patent replaces mechanical solid state joining processes (friction welding, friction stir welding) with an additive manufacturing process that uses controlled energy input and rapid cooling. This substitution enables joining of dissimilar metals with complex geometries that cannot be accessed by mechanical processes, while the process complexity is managed through automated layer-by-layer construction.
4Reliability
If additive manufacturing is used with fast cooling rate, then intermetallic brittle phases are prevented from forming, but process control complexity increases
Solution Approach 1:
The patent implements parameter changes by establishing specific rapid cooling rates (>100°C per second) during additive manufacturing. This controlled thermal parameter transformation prevents intermetallic brittle phase formation and improves joint reliability. The process control complexity is managed through integrated thermal management systems that automatically maintain the required cooling rates.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables strong, crack-free bonding between dissimilar metals, avoiding intermetallic brittle phases and residual stresses, thus enhancing the performance and applicability of multi-metallic articles in demanding geometries and environments.
Implementation Method 1
Additive manufacturing can include a meltpool with a fast cooling rate such that no intermetallic brittle phase forms at the interface between the first metallic material and the second metallic material
Implementation Method 2
additive manufacturing includes laser metal deposition (LMD)
Data Source
AI summary
Methods disclosed herein include using additive manufacturing to create a joint between a first metallic material and a second metallic material that is different from the first metallic material, wherein the porosity of the joint is less than about 0.1 percent by volume measured according to ASTM B-962. The additive manufacturing can be performed such that no intermetallic brittle phase forms between the first metallic material and the second metallic material.